A whole system approach

Charlotte Morton, chief executive of the Anaerobic Digestion & Bioresources Association (ADBA) says we mustn’t forget the bigger picture as we look towards the introduction of mandatory separate food waste collections.

In our last piece for Circular Online, we discussed the importance of separate food waste collections to meeting our carbon reduction targets. This is itself a vital policy priority, but as part of the piece, there are many other moving parts needed to make it a success, and get the most value out of the food waste collected.

Part of this is how we dispose of the waste in the first place, and which system leads to maximum capture, and most efficient processing – what is the best way to ensure the waste gets from kitchen, to bin, to anaerobic digestion (AD) plant, with minimum contamination, especially from plastics?

To bag or not to bag?

We believe the use of compostable bags, or digestible when available, is critical to meeting these objectives. Using compostable bags will not only reduce the quantity of plastics going to soil but send the right message to householders about both single-use plastics and the value of the food waste they are collecting.

And, if the use of compostable or digestible bags is mandated, it will also ensure that local authorities that already provide biodegradable bags, and AD plants that have adapted their machinery, are not left at an unfair disadvantage vis a vis those areas that may still allow other sorts of materials in their food bins.

The process of rolling out biodegradable bags and ensuring they can be processed in recycling will have extra costs for both LAs and AD operators, and the Government should be ready to support the change. This will not just improve the waste management system but also reduce plastic pollution, in line with the European Circular Economy Package.

We’re therefore pleased to see a government commitment to funding biobags in the Resources & Waste Strategy and are working closely with officials to see how AD operators could be financially supported to make any necessary adjustments to their operations.

Cutting out plastic

Concerning the standards of compostable bags, Defra presented a review of standards for biodegradable plastic carrier bags to Parliament in December 2015. One of its objectives is to ensure that these bags, when used for the collection of food waste, do not compromise the treatment of food waste by anaerobic digestion or composting – vital for ensuring contamination of the resultant digestate is minimal.

Soil health in this country is of the upmost importance and we want to ensure that the output from processing food waste through AD plants is a high-quality fertiliser with a strong demand from farmers. For this to be achieved in the most straightforward way, plastics contaminants should not enter the AD process in the first place.

…While some collecting companies and AD plants could perform this sorting, this burden should not be imposed on them and the alternative should be a rapid reduction of single-use plastic across the board, so it does not enter food bins in the first place

The government has vowed to eliminate avoidable plastic waste by 2042, and supermarkets by 2025. This indicates that as a society we either stop using non-recyclable plastic products like straws, carrier bags, plastic cutlery and cling film, or we must find compostable or recyclable alternatives.

More plastics could be recycled if properly sorted in facilities, however the costs of sorting would, at present, be prohibitive. The consistency framework from this consultation should maximise the return of value. Therefore, while some collecting companies and AD plants could perform this sorting, this burden should not be imposed on them and the alternative should be a rapid reduction of single-use plastic across the board, so it does not enter food bins in the first place.

AD and composting in harmony

With plastic contaminants removed from the feedstock, compostable and biodegradable materials, such as alternatives to single-use plastics, could be collected with food waste, removed in the de-packaging process at AD plants and sent to composting facilities.

This would be in line with the EU WFD, Article 22, which states, “Member States may allow waste with similar biodegradability and compostability properties (e.g. compostable bin caddy liners) which complies with relevant European standards or any equivalent national standards for packaging recoverable through composting and biodegradation, to be collected together with bio-waste.”

This would also require regulation of biodegradable plastics and packaging to ensure they meet certain standards. In addition, if further processing of digestate would improve its quality and improve soil health, this should be explored. However, options for upgrading digestate would have an additional cost which Government should be ready to support due to the potential for improved environmental outcomes in agriculture – something ADBA is considering when talking to officials about the proposed Agriculture Bill.

So as we look towards the introduction of mandatory separate food waste collections over the next couple of years, let’s not forget the bigger picture – to get the most out of this valuable resource, and ensure that our soils are plastic free, a whole system approach involving eliminating plastics and using compostable or digestible caddie bags must be taken – without this, we risk repeating the mistakes of the past, and the problem of plastic contamination will continue to haunt. Let’s not miss this opportunity to crack it.

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